'use strict';
function make_num_into_letter(item){
  let num1=item%26;
  let num2=Math.floor(item/26);
  if(num2==0){
   item=String.fromCharCode(num1+96);
  }
  else if(num2==1&&num1==0){
    item=String.fromCharCode(122);
  }
  else if(num2>1&&num1==0){
    item=String.fromCharCode(num2-1+96,122);
  }
  else{
    item=String.fromCharCode(num2+96,num1+96);
  }
return item;
}
function even_to_letter(collection) {
  let result=[];
  for(let item of collection){
    if(item%2==0){
      result.push(make_num_into_letter(item));
    }
  }
  console.log(result);
  return result;
}

module.exports = even_to_letter;
even_to_letter([1,2,3,4,5,6,7,8,9,10]);
